A new class of light emitting and laser diodes is disclosed wherein ballistic (without collisions) electron propagation along the nanotubes, grown normally to the substrate plane on the common metal electrode, provides conditions for the light emission from the nanotubes. The electrons, tunneling from the input contact into high energy states in the nanotubes, emit light via electron energy relaxation between the quantum energy levels existing in the nanotubes due to quantum size effect.In the disclosed devices, planar layer deposition technology is used to form a diode structure with two electrodes attached to the nanotubes ends.